Electronic thermometer with selectable modes

ABSTRACT

An electronic thermometer is configured for selectable predictive modes based upon the same predictive algorithm. A mode selector is adapted for user selection between several modes of operation of the thermometer. Each mode of operation utilizes the same predictive algorithm for estimating the temperature of the subject before the thermometer reaches full equilibrium. Different modes offer users a selection for striking the appropriate balance between response time and precision, based upon user preferences and needs.

FIELD OF THE INVENTION

The invention pertains to the field of electronic thermometers and moreparticularly the field of fast response electronic thermometersemploying a sensor probe.

BACKGROUND OF THE INVENTION

Electronic thermometers are widely used in the healthcare field formeasuring patient's body temperature. Typical electronic thermometershave the form of a probe with an elongated shaft portion. Electronictemperature sensors such as thermistors or other temperature-sensitiveelements are contained within the shaft portion. Additional electronicsconnected to the electronic sensor components may be contained within abase unit connected by wire to the shaft portion or may be containedwithin a handle of the shaft portion, for example. Electronic componentsreceive input from the sensor components to compute the patient'stemperature. The temperature is then typically displayed on a visualoutput device such as a seven, or fourteen, segment numerical displaydevice. Additional features of known electronic thermometers includeaudible temperature level notification such as a beep or tone alertsignal. A disposable cover or sheath is typically fitted over the shaftportion and disposed after each use of the thermometer for sanitaryreasons.

Electronic thermometers have many advantages over conventionalthermometers and have widely replaced the use of conventional glassthermometers in the healthcare field. For example, electronicthermometers do not require costly sterilization procedures and do notpresent the dangers associated with mercury or broken glass causinginjury to a patient. Furthermore, electronic thermometers generally havea faster response time than glass thermometers and provide very preciseand accurate temperature measurement information.

Despite the response time improvements over glass thermometers, someknown electronic thermometers have unacceptably long response time. Thelong response time is primarily due to the thermal mass of the probetogether with the sensor components. The thermal mass of the probe andthe sensor components may take several minutes to reach the actual bodytemperature of the patient being measured. The thermal mass of the probetypically begins a measurement cycle at a lower temperature than thepatient being measured and absorbs heat from the patient until thepatient and the thermal mass of the probe reach thermal equilibrium.Therefore, the thermal mass of the probe prevents the sensor temperaturefrom instantaneously reaching a patients body temperature.

Electronic thermometers in the prior art are known having improvedresponse times that are achieved using a number of different techniques.One technique known in the art employs thermally conductive materialsuch as metal in the probe tip between the patient contact area and thetemperature sensor. Another technique uses a very thin layer of materialbetween the patient contact area and the temperature sensors. Both ofthese techniques improve response time somewhat but still allow time tobe wasted while heat from the patient flows to the thermal mass of theprobe instead of the temperature sensors.

Previously known electronic thermometers have employed electric heaterelements in the probe shaft to bring the temperature of the thermal massof the probe shaft and probe tip closer to the temperature of thepatient prior to taking temperature measurements. Temperature sensorreadings are used in known methods to control electric current to theheater element. Time is saved because less heat must be transferred fromthe patient to the thermal mass of the probe before the temperaturesensors reach thermal equilibrium with the patient.

The response time of electronic thermometers has also been improved bymethods that do not involve heating the probe shaft or tip. Predictivetype thermometers are known for example, wherein a set of earlytemperature measurements are read by the electronics of the thermometerand a mathematical algorithm is applied to extrapolate to a finalestimated equilibrium temperature. Various prediction type thermometersare known which improve response time and provide accurate temperatureestimations. Still other methods of improving the response time ofelectronic thermometers are known which combine heating methods withprediction methods. For example, one predictive-type clinicalthermometer automatically switches between a plurality of predictionfunctions to determine a final predicted temperature. The thermometermonitors the measured results of the thermometer for a set time beforeapplying an initial predictive function to the measured results. Thethermometer then monitors the ability of the initial predictive functionto predict the measured results. Where the measured temperature resultsdo not follow the initially applied prediction function, the thermometerautomatically selects another prediction function. Again, thethermometer monitors the ability of this other prediction function topredict the measured results. This process of monitoring and switchingto another of a plurality of predictive functions continues until thethermometer determines that a satisfactory prediction is achieved orthat a time limit is reached. In other words, without user input orcontrol, the thermometer can select to apply several differentpredictive functions throughout a single measurement process. Thisautomatic switching from one predictive function to another can addmeasurement time and ignores any user preference or input regardingdesirable prediction time or required accuracy.

Even though thermometers have been improved by various methods in theprior art, disadvantages of the prior art thermometers leave room forimprovement. For example, some prior art thermometers still suffer fromrelatively long response times, as judged by the user of thethermometer. For prediction algorithms, the goal of decreased responsetime opposes the goal of increased precision. As response time isreduced, precision decreases, and vice versa. Thus, known thermometerdesigners have had to make a design choice for the user, constructingthermometers that compromise between decreased response time andincreased precision. The problem with making such a choice for allapplications, however, is that different thermometer applications mayhave different requirements and goals. For example, some applicationsrequire a very short response time, but do not require an extremely highlevel of precision. In contrast, other applications do not require ashort response time, but do require an extremely high level ofprecision. Conventional thermometers ignore these user preferences andmay spend more time than a user would prefer obtaining a predictedtemperature. Conversely, a conventional thermometer may not spendadequate time determining a predicted temperature of sufficientaccuracy. A thermometer that allowed the user to determine and adjustthe balance between response time and precision based upon thethermometer application would be useful.

SUMMARY OF THE INVENTION

The present invention is embodied in a prediction type electronicthermometer configured to allow user selection of the desired responsetime of the thermometer and the desired precision of the temperaturereadings. In one exemplary embodiment of the present invention, theapplication of a particular prediction algorithm provides a user withcontrol over the desired precision and the thermometer response time. Auser may select how the data collected by the electronic thermometer isapplied to the prediction algorithm, thereby selecting where thecompromise between the countervailing goals of increased precision andreduced response time is maintained.

In one exemplary embodiment of the present invention, an electronicthermometer comprises a probe adapted to be heated by a subject for usein measuring the temperature of the subject. The electronic thermometeralso comprises at least one temperature sensor for detecting thetemperature of the probe. The electronic thermometer further comprises amode selector adapted for user selection between at least a first modeof operation of the thermometer and a second mode of operation of thethermometer. Each of the first and second modes of operation utilizesthe same predictive algorithm for estimating the temperature of thesubject before the thermometer reaches full equilibrium with thesubject. The thermometer determines the temperature in the second modeof operation more slowly as compared with the first mode of operation,but with greater precision as compared with the first mode of operation.

In another exemplary embodiment of the present invention, a method fordetermining the temperature of a subject with an electronic thermometeris disclosed. The method comprises receiving from a user of theelectronic thermometer a selection between at least a first mode ofoperation of the thermometer and a second mode of operation of thethermometer. The method further comprises collecting temperatures of thesubject measured by the thermometer over time and applying at least someof the collected measured temperatures to a predictive algorithmaccording to the first mode of operation, when the selection receivedfrom the user is for a first mode of operation. The method furthercomprises applying at least some of the collected measured temperaturesto the same predictive algorithm according to the second mode ofoperation, different from the first mode of operation, when theselection received from the user is for a second mode of operation. Themethod further comprises estimating the temperature of the subject withthe predictive algorithm based upon the selected mode of operation.

In still another exemplary embodiment of the present invention, a methodfor determining the temperature of a subject with an electronicthermometer comprises receiving from a user of the electronicthermometer a selection of one of a plurality of predictive modes ofoperation of the thermometer. The plurality of predictive modes ofoperation are arranged for selection along a continuum from a shortestmeasurement duration and a standard-precision measurement to a longestmeasurement duration and a highest-precision measurement. The methodfurther comprises collecting temperatures of the subject measured by thethermometer over time, applying at least some of the collected measuredtemperatures to a predictive algorithm according to the predictive modeof operation selected by the user, and estimating the temperature of thesubject with the predictive algorithm based upon the selected predictivemode of operation.

Other exemplary features of the present invention will be in partapparent and in part pointed out hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective of an electronic thermometer of one embodimentof the invention;

FIG. 2 is a perspective of a probe of the electronic thermometer of FIG.1;

FIG. 3 is an exemplary display of the electronic thermometer of FIG. 1;and

FIG. 4 is a flow diagram of a method of one embodiment of the invention.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawings.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings and in particular to FIGS. 1 and 2, anelectronic thermometer constructed according to the principles of thepresent invention is indicated generally at 1. The electronicthermometer comprises a temperature calculating unit, indicatedgenerally at 3, that is sized and shaped to be held comfortably in thehand H. The calculating unit 3 (broadly, “a base unit”) is connected bya helical cord 5 to a probe 7 (the reference numerals indicating theirsubjects generally). The probe 7 is constructed for contacting thesubject (e.g., a patient, not shown) and sending signals to thecalculating unit 3 representative of the temperature. The calculatingunit 3 receives the signals from the probe 7 and uses them to calculatethe temperature. Suitable circuitry for performing these calculations iscontained within a housing 9 of the calculating unit 3. The logic in thecircuitry may include a predictive algorithm for rapidly ascertainingthe final temperature of the patient according to two or more modes ofoperation, as will be discussed in greater detail below. The circuitrymakes the calculated temperature appear on a display 11 (e.g., an LCDdisplay) on the front of the housing 9. Other information desirably canappear on the display 11, as will be appreciated by those of ordinaryskill in the art, and discussed in greater detail below with referenceto the display of FIG. 3. A panel 11A of buttons, or other userinterface devices (e.g., switches, toggles, knobs, dials, touch screens,keypads, etc.) for operating the thermometer 1 is located just above thedisplay 11. As would be readily understood by one skilled in the art,other arrangements of the display and panel can be utilized withoutdeparting from the scope of embodiments of the invention.

Referring again to FIGS. 1 and 2, the housing 9 includes a compartment,or slot, (not shown) generally at the rear of the housing that canreceive a distal portion of the probe 7 into the housing for holding theprobe and isolating the distal portion from the environment when not inuse. FIG. 1 illustrates the probe 7 being pulled by the other hand H1from the compartment in preparation for use. The housing 9 also has areceptacle 13 that receives a suitable container, such as a carton C ofprobe covers. In use, the top of the carton C is removed (not shown),exposing open ends of the probe covers. The distal portion of the probe7 can be inserted into the open end of the carton C and one of the probecovers can be captured (e.g., snapped into) an annular recess 14 (FIG.2). Ejection members 15 are located at the junction of a handle 17 ofthe probe 7 with a probe shaft 19. The probe shaft is protected fromcontamination by the cover when the distal portion of the probe shaft 19is inserted, for example, into a patient's mouth. A button 21 on theprobe handle 17 can be depressed to cause the ejection members 15 tomove for releasing the probe cover from the probe shaft 19. Subsequentto use, the probe cover can be discarded. Other ways of capturing andreleasing probe covers may be used without departing from the scope ofthe present invention.

In use, a metal tip 25 (e.g., aluminum) at the distal end of the probeshaft 19 is heated up by the patient and the temperature of the tip isdetected, as will be described more fully hereinafter. The probe coveris preferably made of highly thermally conductive material, at least atits portion covering the tip 25, so that the tip can be rapidly heatedby the patient. The tip 25 also includes a heater element (not shown)used to heat the probe 7 to near the temperature of the patient toprovide a faster response time for the thermometer. One or moretemperature sensors, such as a tip temperature sensor and a proximaltemperature sensor may be disposed within the probe for connection to atemperature prediction component (not shown). In at least oneembodiment, the temperature sensors are connected to a microprocessorsystem which performs the functions of both a heater control circuit anda temperature prediction component. The proximal temperature sensorprovides a signal indicative of the heater temperature for use by theheater control circuit in computing a heater current control value. Theproximal temperature sensor may also provide a signal indicative of theheater temperature for use in a temperature prediction algorithm.

The base unit 3 houses a power supply and electronics for the heatercontrol circuit and the temperature prediction component. The helicalcord 5 carries power from the base unit 3 to the probe 7. While not inuse, the probe 7 may be stored within the slot in the base unit 3. In atleast one embodiment of the invention, the slot may include a switch totrigger initiation of the heater control circuit so that the heaterelement may be powered up beginning when the probe 7 is removed from thebase unit 3. The electronic thermometer 1 also includes a dockingstation 27 for receiving the temperature calculating unit 3, such as forstoring the temperature calculating unit, recharging of the powersupply, establishing communication between the thermometer and thedocking station, and securing the temperature calculating unit, amongothers.

Generally, input from the temperature sensors in the probe 7 is used bya temperature prediction algorithm to determine a predictive temperatureand output the temperature to the display 11. In at least oneembodiment, interim output display signals are continuously updated asthe temperature sensors reach equilibrium. In an alternative embodiment,no output is displayed until after a temperature reading is determinedaccording to a mode of operation selected by the user. The temperatureprediction algorithm monitors the probe 7 temperature in time and thenuses that information to predict the final stabilization temperature.The prediction algorithm can take many forms and may be based upon manyvariables, such as heater temperature, probe tip temperature, probecover temperature, skin temperature, body temperature, tissuecapacitance, cover capacitance, probe tip capacitance, body skinresistance, skin-cover resistance, cover-probe resistance, probe-heaterresistance, and time, among others. As an example of such a predictionalgorithm, Applicants hereby incorporate by reference co-assigned U.S.application Ser. No. 09/893,154, entitled Probe Tip Thermal Isolationand Fast Prediction Algorithm, issued Jan. 4, 2005 as U.S. Pat. No.6,839,651. One skilled in the art would readily understand how to createand implement such a prediction algorithm with reference to theabove-noted application.

Referring again to the panel 11A of the electronic thermometer 1depicted in FIG. 1, one exemplary embodiment of the electronicthermometer also comprises a mode selector 11B adapted for userselection between a first mode of operation of the thermometer and asecond mode of operation of the thermometer. Each of the first andsecond modes of operation utilizes the same predictive algorithm forestimating the temperature of the subject before the thermometer 1reaches full equilibrium with the subject. Generally speaking,prediction algorithms are utilized to achieve a primary goal ofdecreased response time. The goal of decreased response time, however,opposes the goal of increased thermometer precision. Generally, asresponse time is reduced, precision decreases, and vice versa. The firstand second modes discussed herein allow a user to select between thefirst and second modes, which each feature a different balance betweenspeed and precision. In the present example, the thermometer 1determines the temperature in the first mode of operation more quickly,as compared with the second mode of operation. Because the temperatureis determined more quickly, it is also determined with less precision,as compared with the second mode of operation. For particularapplications, however, such a level of precision is sufficient, andpreferable because of the decreased time required to estimate such atemperature.

Referring now to FIG. 3, the exemplary display 11 will be described infurther detail. In the present example, the display 11 of the electronicthermometer 1 comprises a visual indicator 31 indicating the mode ofoperation selected by the user. The visual indicator 31 includes twoportions, a first mode indicator 31A and a second mode indicator 31B.Each of the indicators is represented by a particular icon, indicativeof the type of mode selected by the user. For example, because the firstmode determines the temperature more quickly, the first mode indicator31A is depicted as a rabbit, while the second mode is depicted with noicon. This icon serves as a reminder to the user regarding thecharacteristics of the selected mode. The visual indicator 31 alsoincludes a direct mode indicator 31B for indicating that the thermometeris functioning in the direct mode whereby no prediction algorithm isutilized. The display 11 can include other features, such as a numericdisplay 33 (e.g., a seven, or fourteen-segment display device) fordisplaying temperature, a timer icon display 35 for displaying when apulse timer is being used, a body site icon 37 for displaying thecurrent setting for the portion of the subject being tested, and a probeicon 39 for indicating when a probe cover should be installed orremoved. Other features may be incorporated into the display 11 withoutdeparting from the scope of the embodiments of the present invention.

In still another exemplary embodiment, the mode selector 11B is adaptedfor selecting between a plurality of predictive modes of operation ofthe thermometer 1. As described in greater detail below with respect tothe exemplary methods of the present invention, the plurality ofpredictive modes of operation are arranged for selection along acontinuum from a shortest measurement duration and a standard-precisionmeasurement to a longest measurement duration and a highest-precisionmeasurement. In this manner, manipulation of the mode selector 11B isrelatively straightforward, allowing the user to appreciate that movingone direction on the continuum will lead to shorter measurement durationand average precision, while moving in the opposite direction on thecontinuum will lead to longer measurement duration and higher precision.Each of the plurality of predictive modes of operation utilizes the samepredictive algorithm for estimating the temperature of the subjectbefore the thermometer reaches full equilibrium with the subject. Byapplying different data to the same predictive algorithm, temperatureestimates of varying precision and data collection duration may beachieved. This exemplary embodiment also includes a visual indicatorindicating the mode of operation selected by the user, similar to thevisual indicator 31 of FIG. 3. As would be understood by one skilled inthe art, a visual indicator associated with the present embodiment wouldrequire more than three portions, but could be designed in a similarmanner, demonstrating the continuum described above.

For the present embodiment, the mode selector 11B itself may be formedin a number of different ways. For example, the mode selector 11B maycomprise a rotary dial (not shown) adapted to be rotated to a pluralityof positions corresponding to the plurality of predictive modes ofoperation. In another example, the mode selector 11B may comprise amovable selector (not shown) adapted to be moved to a plurality ofpositions corresponding to the plurality of predictive modes ofoperation. In still another example, the mode selector 11B may comprisea plurality of buttons, each button corresponding to one of theplurality of predictive modes of operation. In any event, any type ofmode selector 11B adapted for selecting each the plurality of predictivemodes may be utilized without departing from the scope of the presentembodiment.

Turning to the embodied method of the present invention, a method fordetermining the temperature of a subject with an electronic thermometer1 utilizing a two-mode thermometer operation is generally depicted as 51in FIG. 4. The method 51 comprises receiving, at 53, from a user of theelectronic thermometer 1 a selection between at least a first mode ofoperation of the thermometer and a second mode of operation of thethermometer. As discussed generally above, the first mode and secondmode of the thermometer apply different collected data to the samepredictive algorithm. Once selected, the method 51 decides, at 55,whether the mode is based upon elapsed collection time or a total numberof data points collected (e.g., the first mode of operation) or is basedupon meeting an enhanced precision determination (e.g., the second modeof operation).

In either mode, the method 51 further comprises collecting, at 57 and59, temperatures of the subject measured by the thermometer over time.The collecting 57,59 can occur at a constant rate (e.g., each 0.188seconds) or at any number of defined or random intervals, eachassociated with a particular time.

Where the mode selected is based upon elapsed collection time or a totalnumber of data points collected (e.g., the first mode of operation), themethod 51 further applies, at 61, at least some of the collected 57measured temperatures to the predictive algorithm according to the firstmode of operation. Alternately, where the mode selected is not basedupon elapsed collection time or a total number of data points collected(e.g., the first mode of operation), but rather is based upon some othercriteria (e.g., precision of the temperature estimation), the method 51applies, at 63, at least some of the collected 59 measured temperaturesto the same predictive algorithm according to the second mode ofoperation, different from the first mode of operation. The first andsecond modes of operation can differ in any number of ways withoutdeparting from the scope of embodiments of the present invention. In oneexample, the applying 61 at least some of the collected measuredtemperatures to the predictive algorithm according to the first mode ofoperation comprises applying fewer measured temperatures to thepredictive algorithm according to the first mode of operation, ascompared with the number of measured temperatures applied to the samepredictive algorithm according to the second mode of operation. In otherwords, the first mode of operation collects fewer data points, orcollects data for a shorter time, than the second mode of operation.Collecting fewer data points or collecting data over a shorter periodprovides a faster response, while providing adequate precision.Alternately, the second mode functions according to the precision of thepresent prediction, which may provide a response in a suitable, yetlonger, time with enhanced precision.

Continuing with the first mode, the method 51 continues by determining,at 67, if the collection time limit has elapsed or the data point limithas been reached. For example, the method 51 can determine if the methodcollected N number of measured temperatures. In another example, themethod 51 can determine if collection 57 has occurred continuously forat least about S number of seconds. If no is the answer to either ofthese inquiries, the method 51 returns to the collecting 57. But if yes,enough data has been collected or adequate time for data collection haspassed, and the method 51 terminates, or truncates, the collecting 57 oftemperatures and continues with estimating, at 69, the temperature ofthe subject with the predicted algorithm by applying the N number ofcollected measured temperatures or the collected measured temperaturescollected for at least about S number of seconds. In this first mode ofoperation, the predictive algorithm estimates 69 the equilibriumtemperature with the data collected thusfar, without regard for theprecision or accuracy of the estimated temperature. Such an estimate 69is in accordance with instructions from the user in selecting the firstmode of operation. This termination of the collecting 57 process iscounterintuitive, as the conventional wisdom in temperature monitoringis to strive to collect more and more data in a shorter amount of timeto improve both the precision and speed of the measurement. Terminatingthe collection of temperature data and proceeding to estimate thetemperature with only the data collected up to that point in timeprovides a thermometer capable of adequate precision, while providingresults in a very short time period. In other words, by restricting datacollection to a particular length of time, thermometer response time isimproved and thermometer performance is adequate for the associatedapplication. In an alternative embodiment, aspects of the invention mayapply reasonable bounds on the measurements to prevent reporting clearlyerroneous readings. For example, if the truncated prediction yields atemperature measurement less than 60° F. or greater than 120° F., theprediction algorithm evaluates one or more additional data samples andadjusts the predicted measurement accordingly.

In a more specific example, the estimating 69 occurs when at leastfourteen measured temperatures have been collected. Where temperaturemeasurements occur at 0.188 second intervals, the temperature isestimated at about 2.6 seconds. In another specific example, theestimating 69 occurs when temperature measurements have occurredcontinuously for at least about 2.6 seconds. With the temperatureestimate determined, the method displays, at 71, the estimatedtemperature for the user. In one example, the method further sounds analarm (not shown) when displaying 71 the estimated temperature to alertthe user that the displayed temperature meets the criteria of theselected mode of operation.

Returning to the second mode of operation, the method 51 has alreadycollected 59 the temperatures of the subject measured by the thermometerover time and applied 63 the collected measured temperatures to the samepredictive algorithm as the first mode of operation, but according tothe second mode of operation. In particular, the method 51 continues byestimating, at 75, the temperature of the subject according to thesecond mode of operation. The method 51 continues by determining, at 77,if these temperature estimates meet the precision requirements of thesecond mode of operation. In one example, the estimate of the predictivealgorithm must converge to a precision meeting a minimum threshold. Forexample, final temperature estimates are calculated according to thetemperature prediction algorithm, including determining a goodnesscriterion.

If the goodness criterion indicates that the prediction is acceptablyprecise, then the thermometer 1 displays 71 the estimated temperature.Alternately, if the goodness criterion indicates that the prediction isnot acceptably precise, then the heating element continues to receivepower, the temperature sensors continue to collect data, and thethermometer 1 returns to collecting 59 more data. Utilizing such apredictive algorithm in the second mode of operation, a time of about 4to 11 seconds is needed to present a final prediction of temperature.Depending upon particular variables, the appropriate prediction time mayrange from 3.2 seconds to about 30 seconds. As an example of such aprediction algorithm utilizing a goodness criteria, Applicants herebyreference co-assigned U.S. application Ser. No. 09/893,154, entitledProbe Tip Thermal Isolation and Fast Prediction Algorithm, issued Jan.4, 2005 as U.S. Pat. No. 6,839,651.

In addition to the first and second modes discussed above, the method 51also contemplates an additional direct mode that may be invokedmanually, such as by user selection, or automatically, such as when thepredictive mode is unable to provide an acceptable estimate within aspecified time period. As shown in FIG. 4, if the goodness criterionindicates that the prediction is not acceptably precise, the method 51does not automatically return to collecting 59 more data. Instead, themethod 51 determines, at 81, if a prediction time limit has elapsed.Where the time limit has not elapsed, the method returns to thecollecting 59, applying 63, estimating 75, and determining 77 tocontinue seeking an estimated temperature meeting the precisionrequirements. Where the time limit has elapsed, the method 51 switches,at 85, to a direct mode of operation. The direct mode collects, at 87,temperature data and determines, at 89, if the collected readings meetthe requirements of the direct mode of operation. In one example, thedirect mode does not apply the predictive algorithm, but simply collectstemperature information until the temperature equilibrates with thesubject. This method is highly accurate, but can take significant time,as the probe 7 must completely equilibrate to the subject.

A short summary comparison of the first and second modes follows.Utilizing the same prediction algorithm, estimating the temperature ofthe subject based upon the first mode of operation occurs more quickly,as compared with the second mode of operation. Put another way,estimating the temperature of the subject with the predictive algorithmbased upon the second mode of operation occurs with greater precision,as compared with the first mode of operation.

These methods are applicable to collecting temperatures of a subject andestimating the temperature of a subject. As would be understood by oneskilled in the art, these methods are readily applicable to collectingtemperatures of a patient measured by the thermometer over time andestimating the temperature of the patient with the predictive algorithmbased upon the selected mode of operation. Other subjects, such asanimals, test apparatus, and other devices requiring measurement mayalso be subject to the disclosed methods without departing from thescope of embodiments of the invention.

Embodiments of the present invention further contemplate a methodincluding a plurality of predictive modes. Where similarities existbetween this method and the previously described method, references willbe made to FIG. 4. Such a method comprises receiving 53 from a user ofthe electronic thermometer 1 a selection of one of a plurality ofpredictive modes of operation of the thermometer. The plurality ofpredictive modes of operation are arranged for selection along acontinuum from a shortest measurement duration and a standard-precisionmeasurement to a longest measurement duration and a highest-precisionmeasurement. In this manner, the continuum allows the user to readilyappreciate that moving one direction on the continuum will lead toshorter measurement duration and average-precision, while moving in theopposite direction on the continuum will lead to longer measurementduration and higher-precision. Each of the plurality of predictive modesof operation utilizes the same predictive algorithm for estimating thetemperature of the subject before the thermometer reaches fullequilibrium with the subject. By applying different data to the samepredictive algorithm, temperature estimates of varying precision anddata collection duration may be achieved.

As with the previously described method, the present method furthercomprises collecting 57 temperatures of the subject measured by thethermometer over time and applying 61 at least some of the collectedmeasured temperatures to a predictive algorithm according to thepredictive mode of operation selected by the user. In other words, thismethod includes several first modes of operation as defined by theprevious method 21. The decision box 55 of FIG. 4 would thereforeinclude additional collecting 57, applying 61, and determining 67 pathsin parallel with the path depicted in FIG. 4. Each alternate path wouldcorrespond to a different mode having a different elapsed time limit ordifferent data point limit than the remaining modes of operation. Themethod further comprises estimating 69 the temperature of the subjectwith the predictive algorithm based upon the selected predictive mode ofoperation.

As noted above with respect to the exemplary two-mode methods, themethods described herein are applicable to collecting temperatures of asubject and estimating the temperature of a subject. As would beunderstood by one skilled in the art, these methods are readilyapplicable to collecting temperatures of a patient and other subjects,such as animals, test apparatus, and other devices requiringmeasurement, without departing from the scope of embodiments of theinvention.

Although embodiments of the invention have been described herein for usein the healthcare field, it will be appreciated that application of thepresent invention is not limited to the health care field. Embodimentsof the invention may be used anywhere that fast response electronicthermometers are useful. For example, embodiments of the presentinvention may be used in industrial temperature measurement applicationsand various laboratory applications.

When introducing elements of the present invention or the preferredembodiment(s) thereof, the articles “a”, “an”, “the” and “said” areintended to mean that there are one or more of the elements. The terms“comprising”, “including” and “having” are intended to be inclusive andmean that there may be additional elements other than the listedelements. Moreover, the use of “up”, “down”, “top” and “bottom” andvariations of these terms is made for convenience, but does not requireany particular orientation of the components.

As various changes could be made in the above without departing from thescope of the invention, it is intended that all matter contained in theabove description and shown in the accompanying drawings shall beinterpreted as illustrative and not in a limiting sense.

1. A method for determining the temperature of a subject with an electronic thermometer, said method comprising: receiving from a user of the electronic thermometer a selection between at least a first mode of operation of the thermometer and a second mode of operation of the thermometer; collecting temperatures of the subject measured by the thermometer over time; terminating the collecting of temperatures according to the first mode of operation when the selection received from the user is for the second mode of operation; maintaining the collecting of temperatures according to the second mode of operation beyond the termination according to the first mode of operation when the selection received from the user is for the second mode of operation; estimating the temperature of the subject based upon the collected temperatures associated with the selected mode of operation; and wherein said terminating the collecting of temperatures according to the first mode of operation comprises terminating the collecting of temperatures when the collecting temperatures has occurred continuously for at least one of S number of seconds and N number of measured temperatures. 